The Next Companion
by GallifreyGryffindorGirl
Summary: Shortly after his regeneration, and still learning about his new self, the 12th Doctor meets U.N.I.T agent Cass - not human, not alien, her personal skill set intrigues the Doctor into inviting her on as his companion. Will she show him a life he never thought he could have again, or will he turn on her the same way the reset of her people did? M for later chapters and language
1. Chapter 1

Chapter One

This area of London had been evacuated. They were told there was a gas leak from a major pipe underground that was going to be dangerous to fix. It was a pretty accurate description, Cass thought.

She was the only agent of U.N.I.T still standing. Her comrades, idiots who were unable to work as a team apparently, had fallen some time ago and it had taken all of her supernatural skill just to move their unconscious selves out of the warehouse. Remarkably the freelance ex-Torchwood members where sticking with her and despite her clearly not being human they were able to trust her to work with them anyway – unlike U.N.I.T.

Boy was she nabbed by the wrong alien-fighting association.

Cass lifted her nose to the air, daring not to look behind the crate she and a man who introduced himself as Captain Jack Harkness – though he never specified what he was captain of when she asked, she suspected it was the innuendo squad though – where hiding behind.

"I smell blood. Not human, we defiantly hit it." she called out to the others who she hadn't spotted in their hiding places yet.

"Could be yours, you're not human." Someone called back.

Cass saw Jack glance at her. She shrugged "Even If it had hit me, I'd heal in minutes."

"How can you know that?" he frowned. "Faced giant blue tarantulas before have you? U.N.I.T gets all the fun!"

"No… they managed to procure some of its venom and had it administered to me to see if I could withstand its poison without my knowledge. Knocked me out for a few hours, but I was fine." Cass growled bitterly.

Jack had no time to answer, the spider's legs suddenly made an appearance over the hole and he fired some shots at the edge.

"You said someone was coming to fix this?" Cass asked.

"Yeah. The Doctor. He said not to kill it, he can send it home." Jack grimaced as he fired at a large leg again. They had thought in the beginning that staying away from a venomous spiders giant fangs would be quite easy – however someone of higher knowledge had neglected to explain this certain spider's venom came from the spiny hairs on its body, spines it could fling into the air as a weapon.

"I can do it! I can send you home, you big beauty!" A sudden brash Scottish voice filled the warehouse, and a tall grey haired man darted into the room lightning fast.

"Doctor, don't get too close!" Jack yelled, attempting to leave his hiding place, Cass pulled him back down.

"I'll go, at least I can put up a good fight when that poison gets into me. You just die and come back Jack." Cass winked at his stunned expression, probably surprised she knew about his coming back – but then how many immortal men did U.N.I.T deal with?

Cass sprang up from her spot on the floor, darting across the room just in time to tackle the Doctor and roll on top of him, protecting him from the hairy spines raining down on them. Cass's armoured vest managed to deflect most of the damage, but she took four spines before she rolled off the Doctor, in time to see there was two embedded in his arm. He looked startled at both the tackle from Cass and the sudden burning itching pain Cass knew was burning through his blood steam at that moment. She also became suddenly aware of a new scent in the air – beside the blood, the fear and the sweat there was… sadness… a deep sadness enough for her to be able to scent that… and it was coming, rather surprisingly, from the Spider.

"She's so sad…" Cass muttered, staring sympathetically at the watery arachnids eyes. She'd never liked spiders, but she could suddenly feel the bone cold sadness of the spider now that she was aware of it. "You said you could save her, send her home?" Cass gave the Doctor a side long glance.

He was staring at Cass, she had a spine in her exposed neck one in her waist and two in her legs. He was in agony with just two, and she was still thinking of the Spider with the pain she must be in with four lots of venom dosages in her blood stream.

"Yes. Press the button, throw it into the hole. Then you run." He gasped.

"Then _we_ run." She corrected him, taking the strange little device that looked more like the everlasting gobstopper from the first Willy Wonka film than anything like Alien tech. Still, she pressed the button, threw it into the hole and grabbed the Doctor by his coat half ran with him half dragged him back over to where she and Jack had been hiding.

Something exploded in a shock of colours and began to suck air into it. Cass felt herself grab not just the Doctor but Jack as well, to anchor herself or them she had no idea. When it was done, she finally succumbed to the spider's poison.

Jack and had a new addition to his team – Koai– help the Doctor out of the warehouse where they could get him to a sick bay. He himself scooped the U.N.I.T member Cass into his arms intending to bring her with them.

"But she's U.N.I.T?" someone dared ask him.

"U.N.I.T experimented on her with that poison before sending her in there." Jack hissed, his moral clear that he didn't approve of the testing – even if it had enabled Cass to save the Doctor from worse damage. No one argued with Jack again.

**OoO**

Cass woke feeling groggy. Her body ached, some places – where she remembered being hit with the spiders venomous spines – where completely numb still, but she knew in just a few hours she'd pull through. Faster if she could find a place to shift into her other form.

"Mornin' sleeping beauty." A voice said from a chair beside her bed.

Cass looked up startled. This was not U.N.I.T. Jack Harkness was sitting in soft armchair beside what she now noticed was a collapsible camper bed. There was another bed set up on the other side of the chair holding the Doctor, who was still calmly sleeping.

"We brought you here instead of U.N.I.T taking you. Can't say I approve of them administering venom to a solider just to see if she can survive it."

"The rest of U.N.I.T is not so bad. Just my team leader."

"Then why don't you tell someone what he's doing?"

"Because he'll throw me to the wolves. Literally." Cass laughed at her own joke, knowing no one else got it but still finding it funny.

The Doctor suddenly sat up in his bead, sucking in a deep breath, ice blue eyes looking around wildly. Jack tried his best to get the Doctor to lie back down but he wasn't having any of it. "No, no I-I want out… need… need to go again!" he was muttering.

"What's wrong with him?" Cass asked.

"Just come back from a difficult regeneration – his entire body, personality – has changed… he's still struggling with it." Jack explained as he held the Doctor down with some difficulty. After some minutes, Jack convinced the Doctor to stay put. "I'm going to get you both a good meal, then once out medic has cleared you, then you can go. Alright?"

Both patients nodded.

"Alright. I'm going to get you guys some food. Cass, I want you to make sure he stays put."

"Hey, how come I'm not a flight risk?" Cass asked, teasing as Jack left, winking at her as he did.

"Typical." The Doctor snorted beside her.

"What is?"

"The flirting. That show boy always could get all the pretty ladies to fall down at his feet… all the pretty boys too… pretty anything actually."

"Aw, you think I'm pretty?" Cass teased.

The tops of his ears blushed pink. "That's not wh-"

"I know" she laughed "Doesn't matter. Jack's too young for me anyway."

"I think you mean too old."

"Doubtful, I'd put his age at about… late twenties early thirties?" Cass shrugged. "Not sure exactly, could be older considering he's from a different century and keeps dying all the time."

"That's handy, how'd you know that?"

"I have a good nose." Cass winked at him. "Example, I can tell that wherever you where before here wasn't earth, but it was near a beach."

"Correct. Impressive. Not human?"

"Nope."

"Is that why you could withstand four of those spines before passing out?"

"Yep."

"Should have killed you."

"Yep."

"What are you?"

"Not telling. It's not safe." She suddenly looked around the room, wary and a little afraid.

The Doctor, somewhat understanding her need for secrecy though not entire sure why she thought an enemy might be so close by, chose to ask her a different question. "How old _are_ you?"

She looked affronted, though her bright green eyes said it was only teasing. "Doctor, you should know better than to ask a woman her age!" she giggled, but relented. "Alright, I'm still young for many of my kind… putting it kindly, I was born on the same day as Charles Dickens."

"Char- that'd make you around 202 years old?" he looked shocked.

"Around there I guess, I stopped counting. Still young though for my kind."

"How old does your kind usually live till?" he sounded more than shocked, Cass couldn't quite read his face however… maybe hopeful? Though she hadn't a clue why.

"Well, the oldest I've met was ancient… I wasn't able to put a number on him, but rumour is that he sailed and settled in America with the first colonies." Cass shrugged. "It's hard to age each other after the first hundred years even by scent. Our bodies just keep repairing the old damaged cells making them young again."

"That's better than my way, repetitively dying." Jack said coming back into the room. He was holding plates. "Sunday roast for the patients because Koai likes cooking far too much. Seriously we got a dozen or so lemon cakes if you want them."

The three of them ate, though Cass stayed mostly silent, Jack and the Doctor apparently had some catching up to do. Unfortunately the conversation ended with Jack more worried about the Doctor than before, apparently there where some holes in his memory.

"Enough Jack" the Doctor ended up barking, the Scottish accent making his voice sound a bit more threatening that he probably meant it to be. "For me it's been more than 600 years since I last saw you, of course my memory might be a bit off." He was getting out of the bed now, no amount of Jack stopping him was going to get him down again.

Cass followed suit. Her skin itched, she wanted to get out of there and shift.

"I just want to get back to the TARDIS. I'll be fine once I'm with her."

"I'd still rather you were travelling with someone, you don't seem yourself Doctor…" Jack looked worried.

"Maybe your right Jack. You, do you want to come with me?" the Doctor suddenly approached Cass pointing a finger at her.

"It's rude to point, and you don't even know my name but you're asking me to travel with you?" she frowned, pushing his finger away gently.

"Of course I know your name. It's Cass."

"It's Cassidy actually, but Cass is fine."

"See, knew your name. Come on Cassidy the non-human, constantly afraid of someone discovering what you are… come away with me, away from that fright – travel time and space with me."

"Smooth talking, but you could just say please."

He looked a little annoyed. "Cass will you please come a travel with me?"

Cass smiled brightly. "Sure."


	2. Chapter 2

Chapter Two

He was waiting for her to say it. That statement that gave him almost as big a thrill as when someone would ask "Doctor Who?"

She hadn't said it yet, but she would. Eventually.

"This is your spaceship?" she asked instead. He tried not to look a little disappointed.

"The TARDIS. Time And Relative Dimensions In Space. Time and spaceship" he corrected with a flourish. "So where do you want to go? Another planet? End of time?"

"She's alive, isn't she?" Cass asked suddenly, putting her hand on a metal wall beside a bookshelf, completely oblivious to the Doctors questions. It had taken her long enough to realise that the psychic presence soothing her itching need to shift forms as well as giving her a welcomed feeling was the ship itself.

"Yes, she's sentient. Why?" he frowned.

"Can feel her." Cass turned to him, putting two fingers to her temples and tapping.

The Doctor frowned. The TARDIS was usually a little less welcoming of what she had once called the 'strays' he kept bringing home. "Okay." He stalked towards her suddenly. "You have to tell me what you are Cassidy. The TARDIS has hardly even made contact with anyone else who's come aboard beside myself. You're apparently immune to poisons, and age doesn't ravage you the same way it does a human. So what, pray tell me, are you?"

Cass leaned over the TARDIS railings, winking at the Doctor she said "Wouldn't you just like to know Doctor."

He gave her the look a parent would give a child who didn't want to tell the truth. Before either could say anything again, he suddenly turned and began to fiddle with the screen on the TARDIS console. "If you won't tell me, let's see If the scanner can pick anything up!" he declared almost triumphant at his idea.

Five minutes later he was giving a cry of frustration, running his hands through his silver grey hair, eyes wild he pointed at her "You, you are an enigma!"

Cass just laughed, keen eyesight being able to read the console from her place on the railings. The word 'FAILED SCAN' kept flashing in white, though the humming of the machine suddenly felt more like laughter – she wondered if the machine was playing with him using her.

A phone started to ring suddenly.

Cass looked at the Doctor who was looking at her. After a few minutes of staring at each other, the Doctor went to the doors, opened them revealing deep space, and answered with a gruff "What?"

Cass leaped from the railings to wedge herself snuggly between the Doctor and the TARDIS doors, staring in wonder at the swirling black, red, orange and purples of deep space. Amazing planets she where floating nearby – not one of them looking like earth, but all equally amazing. She was so busy admiring the view, she didn't notice the Doctor on the phone, not even when he hung up.

"Wow…" she breathed.

"Yes. 2000 years of time and space, but I hardly even get to enjoy the scenery. It is still beautiful every time I look." He said in a soft voice just above her ear.

Cass looked up at him, admiring him. Actually, Cass stared, for a 2000 year old Alien he wasn't a bad looker. His eyes where bright and alive, and eyes where the part of a person Cass loved most. She looked away quickly when he glanced down at her, embarrassed about staring.

"Who was on the phone?" she asked instead, doing the same as the Doctor and reaching out to swipe her hand through the mist left behind by a shooting star.

"Random S.O.S call. Better head there soon – good thing about a time machine however is I don't have to leave immediately."

"You don't know who the call was from though?" Cass frowned.

"No. But look, I'm in a flying police box – who do you call when you need help? The police!"

Cass smiled softly. "That's true. Guess I'm just used to being suspicious and cautious." She elbowed him in the ribs softly. "So are we going to go save some idiots then?"

"Finally someone who can identify idiots with me!" he laughed, shutting the TARDIS doors and springing like an oversized cat for the console. The TARDIS rocked as it changed course suddenly. When they landed, the Doctor smiled and took Cass by the hand leading her out of the doors.

They were in an empty cargo bay.

"I feel like that was really anti-climactic." Cass couldn't help but giggled a bit as she dropped the Doctors hand and wandered over to the crates of cargo, looking over the tops of them. "Er… these crates are loaded with what looks an awful lot like guns?"

"I think this is some kind of fleet ship…" the Doctor went across the window. "I'd say we're just outside the Milky Way in fact…"

Alarms sounded suddenly, the Doctor looked around alarmed and Cass – by instinct – ducked into the corner of the crates she was snooping in. Just in time too, as the doors on either end of the cargo bay slid open and soldiers poured into the room – all of them aiming gun's on the Doctor.

"Erm… Hello?" The Doctor said frowning. "Have to say, this is the least welcome, welcome I've received in a long time."

None of the soldiers said anything, instead sinister footsteps sounded and three more men entered, two were also soldiers, and another was a strange looking man with a curling moustache the kind only ever seen on comic book villains. He wore a suit, and when he entered the room he completely ignored the Doctor, instead he approached the TARDIS.

"Ah, a type 40 TARDIS – not only the last of its types, the last of its kind at all!" the man declared proudly. He tried to open the door, but it did not budge. Not even when he tried to push it with its full weight.

"She won't open." The Doctor sounded bored.

"Ah" the man turned on the Doctor. "I almost forgot the pilot – the last Timelord."

"Who your about to bore to death, so why don't you just skip the whole speech thing and tell me who you bloody well are."

The man looked thoroughly insulted, but after a few minutes he said "Just a humble collector. Now, I've heard about you Doctor. Heard you enjoy travelling with a companion. Should I expect a pretty little thing to come out of this museum piece at some point?"

The Doctor didn't reply while soldier's cuffed him. He was staring at the dark spot where Cass hid, watching everything and waiting for a moment. Finally he looked down then back to mysterious moustache man. "No. I am alone."

"Well, I'm not in the habbit of taking live pieces. Take him, chain him, kill him later." The man clicked his fingers and his soldiers jumped up like eager dogs to do his bidding. They dragged the Doctor out of the room – the man laid a soft hand on the TARDIS again before he left. "Find something to get these doors open, laser saw or something." Cass heard him saying as he walked out of the doors.

When she was sure they were gone, Cass took a deep breath. Her sensitive ears couldn't hear anything anymore, nothing but the hum of the TARDIS and the gentle groan of the bigger ships engine. Cass came out of her hiding place and put a hand of the TARDIS herself, swearing she could feel a hum of life in the wood. "Alright big Blue, I guess I'll go get the Doctor and we'll get out of here eh?" she whispered.

_Protect him. _

Cass gasped, pulling away from the wood a fraction. She looked around, knowing there was no one around but her and the TARDIS anyway.

_Protect him. _

The physic message between her and the ship sounded in her mind again, a gentle but commanding voice. Cass nodded. "Okay."

Cass returned to her hiding place, and pulled off her clothes. Naked and more than a little self-conscious, she began to breathe deeply and calmly. Within a couple of minutes Cass felt the change over come her – muscles budging, her spine and teeth lengthened, nails hardening into claws. Within a few minutes Cass was shaking her black furred body standing in the form of a giant black wolf.

Cass had to sit for a moment and use her hind leg to scratch behind her ears, getting rid of the last tingle from the shift, before she set her nose to the ground, following the scent of the Doctor.

OoO

The Doctor was chained by his hands to a pipe. Not his most dignified moment. And yet he couldn't help but be dryly amused by how short this regeneration would have lasted If he was indeed to die right here right now.

He thought about Cass who'd had enough sense to keep her mouth shut when she hid behind those crates. He hoped her sense continued and she got back into the TARDIS. The TARDIS would take her back to Jack, keeping her and the ship away from this idiot collecting maniac.

The door of the room slid open, three soldiers arrived, lining up and aiming their guns at him.

"Oh come now this is hardly sporting." The Doctor frowned. "At least un-cuff me."

The door of the room slid open again, causing them all to turn in question, but no one entered. The Doctor thought he saw a shadow slink to the back of the room, but it may have been a trick of the light.

The soldiers took their positions again, fingers on the triggers, the Doctor shut his eyes, when a snarl rumbled around the room.

Cass leaped from her hiding place, she caught the first gun in her jaws, crushing the barrel under her teeth as she skidded across the floor. She landed in front of the Doctor, standing with her tail up and head down, protecting him. The soilders where a lot more trigger happy to shoot a giant wolf – they always are actually – so Cass moved quickly, she tripped up the last two soldiers simply by running at them. She found that soldier's where a lot less accustom to shooting charging wolves than hunters where. These soldier's soon ran without their guns to protect them.

Cass approached the Doctor, thought he did back up for a second. Cass stopped approaching him until he looked at her and asked "Cass?"

She yipped, wagged her tail, and leaning against the wall tried her best to reach his cuffs and break them, but it was no use.

"Cass, can you see if you can reach my sonic screwdriver in my jacket pocket?" the Doctor asked, his voice smoothing calm as though he was worried starling her would make her rip his throat out.

Cass moved slighting, one huge paw against the Doctors chest – she tried not to lean on him too much, she'd broken rib cages with her paws before – it took some manoeuvring be she managed to use her nose to push the screwdriver from his pocket, letting it fall to the floor she picked it up with her teeth and after stretching up the wall again, placed it into his reaching hand. A few seconds of a little 'wurring' noise and the cuffs on his wrists sprang open.

"Well come on then, no doubt those executioners you scared away are going to come back with reinforcements – and I'd rather get to the TARDIS before they try to laser cut her. She won't like that."

Cass snorted in agreement, leading the way back through the shit the cargo bay, ears alert for footsteps other than their own and nose twitching. Luck was on their side this time however at they reached the TARDIS with no other troubles. Cass had to retrieve her clothes from behind the crates, much to the Doctors confusion.

When the TARDIS doors closed behind them he said "Safe in here, nothing can get through those doors – not even a Dalek and believe me they've tried." He paused at his controls to take a look at the monstrosity of a wolf sitting by the armchair with a bunch of clothes hanging in its mouth. If he paused to think about her as just a wolf rather than also a woman he could admit that she was quite beautiful – when she moved, despite her huge size, she was graceful and her fur was completely liquid black, expect for two white spots over the bright green eyes that watched him – eyes that still belonged to the human Cass.

"You might change back now Cass?" the Doctor said after minutes passed, confused as to why she hadn't.

Cass made a coughing sound a few times, pawing at the clothing she had dropped to the floor of her feet. Unfortunately the Doctor didn't seem to understand what she meant, and despite the fact she suspected he would be uncomfortable with the nudity of a woman he hardly knew, she shifted back. The shift back to human was always easier, more of a bubbling sensation than the painful pull.

When she regained human form she was sitting with her back to the Doctor, though she looked over her shoulder and was amused to see his face blushing bright red as he turned away from her.

"Honestly Doctor, anyone would think you'd never seen a naked woman before." Cass teased, turning back around to pull in her clothes.

She didn't see the Doctor look back over his own shoulder at her, smirking.


	3. Chapter 3

Chapter Three

Cass and the Doctor where sitting in the TARDIS kitchen – which was remarkably old fashioned Cass noticed for such an amazing ship. However, the Doctor did make an amazing cup of tea.

He'd asked if he could re-scan her with the TARDIS, she'd allowed that and it now showed her DNA as human/canine. He though the ship was just trying to make it look like she had always known – but Cass had a feeling the ship really had known what she was, but couldn't pass the opportunity to let the Doctor be confused for once.

"So your what a werewolf?" the Doctor asked "Because I've seen a werewolf before and he was much meaner then you. He had a whole domination plan that involved infecting the Royal Family."

"Probably not a werewolf then, most of us just want to be left alone. And we don't use the term werewolf – we prefer to be called Otherkin."

"Why?" he sounded genuinely confused.

"There are a lot more werecreatures out there than just wolves you know, and Wereturtle sounds ridiculous, so we chose to call ourselves Otherkin." Cass laughed.

"Wereturtle? Really?"

"Yeah, where do you think the idea for teenage mutant ninja turtles came from?" Cass said with a completely straight face. The Doctor was looking completely stoic, as if not sure if she was joking or not.

"I've travelled earth for years, how have I never come across one of you before?" The Doctor genuinely sounded outraged with himself.

Cass just shrugged again. "I'm not sure about recent years, but most Otherkin tend to live in community's completely made of other shapeshifters, completely away from humans. Keep to yourselves and no one gets hurt mentality."

"So why where you with U.N.I.T?"

Cass looked away from him then. "They didn't know what I was. And others of my kind aren't exactly welcoming to me."

"Why?"

"Not now Doctor, I just told you a secret that could get me killed if anyone ever find out what I told you, let me keep some mystery." Cass smiled softly, her eyes sad. She managed to regain her perky happiness back within a few minutes. "What about you Doctor, what's your story? Jack said you'd just had a difficult regeneration, what does that mean?"

"Something similar to you I guess. I don't die, I regenerate. Change my entire body, face even some of my mind."

"Huh" Cass sipped her tea, staring at him over the cup. "And if I hadn't thought the two hearts thing was a big give away that your alien – that defiantly would."

"How did you-?" he frowned, he'd not told her about his hearts.

Cass grinned and tapped her ears. "All the better to hear you with my dear."

Cass sneezed as the Doctor lead her by the hand back to the TARDIS. He was grinning, she was trying to pick mud out of her hair.

"Seriously, only you can get us buried alive!" Cass said smiling through her annoyed tone of voice. She had to admit that now she was back above land the situation had been quite funny – though it wasn't at the time.

"Oh come now, that was exciting. You said show you something exciting." The Doctor teased.

"I didn't say get us buried alive, and I know you found it exciting. Being pressed so close together really isn't the best way for a man to hide his attraction to a female – even if they are buried underground and running out of oxygen at the time." Cass teased, winking at the Doctors growing blush.

"Be quite Cass."

"You're still just a male Doctor, no need to get embarrassed." She jumped up before he could scoot away and pecked his cheek. She'd found in the few weeks they'd been travelling together that the Doctor wasn't really a touchy feely person – though after the evidence of his arousal at being pressed so close to her body she could understand why. He didn't seem comfortable in his own skin at all. "I'll be in the kitchen, I fancy cooking a meal tonight – not that I don't like you popping us off to all these alien café's and such. I just don't really fancy having a dinner that tries to run away from me again – that's only fun in wolf form."

"It's been awful long time since anyone's cooked in there…" the Doctor confessed. He was tugging at the collar of his shirt, face still a little pink, but Cass chose to ignore his reaction to her earlier teasing.

"Well this will be fun then wont it. I went to a market when you were off annoying that fisherman yesterday when you stopped on earth for milk." Cass smiled, walking off towards the kitchen.

When she was gone the Doctor let out a deep breath he had been holding since she pecked his cheek. He had only been travelling with the shape shifting girl for little over a month and a half, but she was already beginning to change him, he could feel it. His regeneration had left him angry, annoyed and cautious of letting people as close as his previous face had allowed the Ponds. Yet, there was something about Cass… it was like she was made to travel with him. She asked the right questions, she kept her mouth shut when she knew she should, she brought out his better side just like any of his other companions but, more. He also had to admit that having a companion that could hear and smell better than you, and spent half her time in the form of a formidable looking wolf with wicked fangs and claws, was pretty hand dealing with troublemakers.

Yet he had to admit there was hardly anything he knew about this girl other than her being 202 years old, a U.N.I.T agent, and she was unwelcomed by her fellow shape shifters for reasons she didn't want to explain. Despite this, he trusted her almost completely – more shockingly, the TARDIS seemed to be able to and enjoy communicating with her. He'd caught the wolf girl conversing with mid-air a few times – particularly in the kitchen and library. Cass had explained the ship could usually get the odd message through to her telepathically.

Sometimes the Doctor dared to think he might be starting to feel something for Cass. He walked around the console room now, watching as he searched the entire universe for a trace of Cass's history anywhere – despite knowing U.N.I.T had done a good job at wiping her from existence. She was pretty, he thought not for the first time, that her features that may have displeased someone else where what made her attractive to him. He liked that her pale round face was splattered with a dozen or so freckles of different shades and sizes, and he liked that he mane of black hair was somewhat naturally messy and thick enough to make it appear _big_. She was petite, about five foot three or under, but she never let it seem like a problem. He was far taller than her, yet if she wanted she let him know when she was in charge of a situation, usually by grabbing him by the front, dragging him down to her size and growling at him in a canine voice. He loved her over all enthusiasm for their adventures, she was brave and optimistic and somehow managed to find a joke in everything – enough to make even their villainous opponents grin sometimes! Yes the Doctor could feel himself falling for Cass, and he couldn't even help himself.

It was at the end of his thoughts about Cass that he found himself standing in the kitchen, watching her humming and cooking at the stove he'd not even dusted in hundreds of years. It was a miracle in itself that the TARDIS remembered to include a stove whenever she redecorated.

"Smells good" he said announcing himself as he sat in a stool in the corner.

He saw Cass jump a little at his voice, she looked over her shoulder with a blush. He was secretly glad he could still sneak up on someone with wolf-like hearing. "Thanks" she said, laying stakes into a frying pan. "I was an army chef before U.N.I.T picked me up. Always made sure my men where well fed, we were fighting a war after all."

The Doctor frowned a little. He didn't like soldiers, and had disliked it knowing she was a U.N.I.T solider, he disliked it even less knowing she was in the army before that. "You were a solider?" he asked, his voice letting her know his displeasure, despite trying to keep it out of his voice.

Cass turned to look at him, removing the apron she was wearing. "No, I just told you I was a chef in the army – they were soldiers. I was just fighting the war on getting men to eat their vegetables. I refused to take part in the war." She cocked her head to one side in a very dog-like manner. "Is that a problem?"

"No. I just don't like soldiers."

"I was a U.N.I.T solider when we met." She pointed out.

"Yeah I know, but you were mistreated by U.N.I.T. You were like their experimental non-human solider."

"So what, you where saving me from U.N.I.T?" Cass asked, a little dismayed.

"No, and yes… I don't just take anyone to travel with me Cass."

They sat for a little in awkward silence, Cass occasionally poking the stakes she put in the frying pan.

"Why don't you like soldiers?" she asked the silence.

"Soldiers take life at the order of another who probably had his orders from someone else. Sometimes it's completely justified, sometimes it's not. I'd rather preserve life than take it at the whim of someone else. I don't lie, I've killed before. But I don't like killers."

Cass paused, she was putting the stakes onto plates she had found that weren't too dusty. She carried on dishing out food, pulling vegetables out of the oven and dishing those too, until she finally carried the two plates over to the table where the Doctor sat.

The Doctor wasn't stupid. He could see in the way Cass sat across from him, not speaking with was a new thing for her, and not looking at him that something he said had struck her heavily.

He didn't ask, he just waited. If she wanted to speak, she would.

They ate in mostly silence, speaking only when Cass collected the dishes to wash. "Thanks, that was amazing Cass, you're a good cook."

"Thank you" she mumbled quietly.

She didn't say anything as the Doctor hung around for a while, watching he wash the dishes he hadn't known he had quietly. She didn't even say anything when he finally, reluctantly, left the room for the library.

Fifteen minutes later the Doctor became aware of Cass standing near him in the library. She was biting her lip with worry, until she became aware that he was watching her from his seat on the sofa.

"Do you really hate killers?" she asked, her voice a ghost of what it usually was.

"That depends on the situation Cass." Was all he could answer, starting to frown and worry.

"Doctor, I-" she took a steadying breath, looking him in the eyes she said "I killed my family."


	4. Chapter 4

Chapter Four

Cass and the Doctor sat in the Library, she was tense about his reaction to her revelation, he was shocked. Of course he'd known Cass was probably a killer, half of her was of course an animal, a territorial predator at that, and she had explained that Otherkin where prone to violence around each other. But to kill her family?

"What?" he asked, no emotion in his voice.

Cass worried her lip, sitting opposite him in a chair, she fiddled her hands together. "Otherkin metabolisms don't allow us to get sick, or at least it doesn't usually." She began. "But when I was eighteen, my entire clan got sick. I'm not sure what it was, but it started off with just one or two having a more fragile temper than usual… then more began displaying the same symptoms… they began fighting, slaughtering each other for no reason other than because they were there. My clan was mostly wolves, but we had a few other species there too. I wasn't the only one who seemed immune – my cousin was a crow shifter, she didn't get sick either. She helped me cage our families when they got sick – we were waiting for help to come from the outside, but before anyone came to help, the ones we caged broke free. My cousin wasn't fast enough, and she was no match for the wolves. I tried to save her, I really did, but they got her before I could, killed her almost instantly… I had no choice. I fought so they couldn't kill me too – I shouldn't have survived, but the sickness drove them mad, they were unable to fight and kill like they could when they were well, and I won… I won by killing them…" she sighed, she had stopped looking him in the eyes while she was speaking instead choosing to look at her feet. "While I was sitting in the middle of all that… help finally arrived. I was put on trial and banished because half agreed my actions justified, and half wanted me killed. That's why no other shifters will give me the time of day."

"Cass…" The Doctor said after a few minutes. "If they were sick, it wasn't your fault…"

Cass nodded, though she wasn't looking at him. "I know Doctor, I do. In fact I'm sometimes glad that my actions stopped whatever disease that was from spreading to other shifters outside our clan – that would have been disastrous. But that doesn't stop me feeling horrible and guilty about it. And I thought you'd prefer if I told you the truth rather than finding out some other way."

"Ah well, U.N.I.T did a good job at wiping your past from any records." The Doctor tried making a joke.

"I figured you'd try looking me up." Was Cass's reply with a wry smile.

The Doctor sighed. "Cass, look at me." He said, wanting to see her vibrant green eyes again.

She did and he sighed. "Cass, for centuries I believed I was responsible for killing my entire species. That I was the last of my kind and that it was completely my fault. I did that because of a war that was destroying everything. So yes, I understand what you did, and I understand that it was not your fault."

A little light came back to her sad green eyes. "What a pair we make eh?"

"Considering I'm an alien with two hearts, and you spend half your time shedding fur all over my ship, I'd say an odd pair." The Doctor grinned.

Cass punched his arm lightly. "It's your fault I'm shedding. My body can't tell what season it is because you keep taking us to summer, then winter, then summer again."

Cass lay in her bed in the TARDIS, tossing and turning. Tonight it seemed that old blue was determined she should not be able to sleep and had cranked the heating up high, causing Cass a great deal of discomfort.

It wasn't just the room temperature that was keeping her awake of course. Cass's mind was wandering and not in a good way. She couldn't help but think about the Doctor in ways that she hadn't thought about a man in a long time. Of course, he was the only person she had been around for longer than a week it was understandable that she would develop an attached attraction to him wasn't it?

Cass rolled over, wiping with disgust at her head which was slick with sweat. Lovely, she thought. There could of course be another reason for her sensitivity to the heat tonight, and her wandering thoughts, but she didn't want it to be that so she tried to ignore it.

Another hour passed, Cass still couldn't sleep. Irritated at her suspicions and wandering mind, she threw the blanket back and got out of the bed. She stalked down the corridors of the TARDIS suddenly knowing a way to check her suspicions before she did something stupid because of them.

"Alright big blue" she said quietly in the console room, ears and eyes alert for signs of the Doctor. "I know you can probably check my body for chemical and hormonal imbalances. I also know you're aware of what I'm looking for, so don't suppose you'd like to help me out here?"

The screen of the console span around to face her, flashing the word 'scanning'. Eventually it showed up a bar graph of the different hormone levels in her own body. "Of fuck…" Cass groaned at the results.

It was the middle of the night, at least she thought it was things like night and day are hard to tell in the middle of deep space, but Cass headed for the library anyway. She knew she wouldn't sleep anymore, and she also knew she had to explain to the Doctor why she was about to start acting very strange, and hope he would understand…She could also understand if he recommended locking her in her room for the next few days however.

He was in the library, luckily. He claimed to have a bedroom somewhere, though she'd only ever seen him catnap in the library. Right now however he was reading a large book. He looked up at her approach, eyebrows raising in surprise as he looked her up and down. Cass wished he wouldn't do that right now – any other time she'd have been curious so his glances – however now she just froze in her step fighting to control her body.

"You look hot." He said simply, returning to his book.

"What?" Cass squeaked.

"Oh er, temperature wise of course." The Doctor blushed a bit.

"Right. Okay."

"I was going to wait until morning to wake you, got a phone call from some friends who're having a little problem. Asked if we'd go take a look. You up for an adventure?"

"Not really. I have a problem." Cass bit her lip.

His book snapped shut abruptly and he turned to her, giving his full attention. "Cass what's wrong? Are you sick? I know a great hospital on New Earth. Actually it's called new new new new –"

"Doctor" Cass cut across him, trying not to sound pissed. "That sounds really interesting and all, but it's a shape shifter thing. I'm going into heat – so I'm going to be acting well… weird for a while."

The Doctor looked…well… stunned. "Ah- so – uh…"

"Don't worry, it'll pass in a day or two."

"So… is there something you want me to do?"

They both blushed at the way that could be interpreted.

"If I say run, run fast and far. I don't like this, I don't like knowing I'm going to embarrass myself."

The Doctor gave a grin. Usually he was the one telling people to run. "You still want to go on an adventure? Might take your mind off things?"

"_When_ are we going?" Cass grinned taking a slouched seat on the couch near him.

"North East England, 1817."

"Ah, I do not remember it."

"How old where you then?"

"Five I think… maybe six, depends what month we go in doesn't it?"

The Doctor smiled and returned to his book. Two thousand year old and she was still not done reading the entire TARDIS library. He had a hunch that she kept adding new books just to spite him every time he got close to reading them all. It didn't matter, it stopped him getting bored when there was nothing to do but float around in space.

Something touched his leg.

Startled the Doctor jumped a little, looking down however he smiled a fraction. Cass was asleep, though her head was nuzzling his leg slightly.

"Do I really have to wear this goddamned bonnet? It itches like mad, and it's getting in the way of my ears."

"Do you have to keep complaining? It's the fashion, you should remember it. Anyway it makes you look cute for a change."

Cass looked affronted as they say in a little pub in 1817. Apparently the only Victorian dress the TARDIS could find in her vast wardrobe had been a gorgeous red corset dress that Cass was embarrassed to admit made her look like she had far more cleavage than she actually did. It was earning her far more stares than she cared to have – even the Doctor had glanced a few times – apparently the ship had no care about Cass's mental state while she was going through the heat. Not to mention the dress had been paired with a giant lace monstrosity of a hat/bonnet.

"Yes well luckily when I was a pup I didn't have to wear giant lace bonnets." She crossed her arms at him. "Anyway I can look cute whenever I want, don't need a bonnet for that. I just haven't tried to look cute for you… yet."

The Doctor's eyebrows raised and he leaned just as close to her- their noses almost touching. "Cass, I'm going to assume that was your sudden hormone imbalance speaking." He leaned away, smiling slightly.

If Cass had been in her regular mind she would have blushed. However in the heat her wolf instincts mostly took over and instead she was mildly irritated that he hadn't responded to her flirting.

Cass froze suddenly. The hair on the back of her neck went up and almost of their own accord her lip pulled back from her teeth in a snarl.

The Doctor looked shocked. "Cass-?"

She was up and out of her seat, moving to his side of the table and sitting on the bench seat beside him so her back could be to the wall giving her an almost full view of the pub in which they sat. she wasn't oblivious to the fact her new seat cornered the Doctor between her, the walls and the table, an instinctual urge surged in her to protect him like he was her pack… which she supposed, he now was.

"Sorry." She breathed, still inhaling deeply through her nose trying to scent exactly where the danger was.

"What are you doing?" he asked not too quietly.

"Just scented another supernatural. Kind of an instinct urge to stay on guard… I wasn't accepted in 2014 by all shape shifters. In 1817, no supernatural species accepted each other. We were constantly fighting with each other."

The Doctor mumbled something like 'can't take you anywhere' but she wasn't really listening anymore.

In fact she was paying him so little attention she didn't notice people joining their table. Not until the Doctor's hand patted her leg under the table in the 'you're being rude' kind of way. She jumped high and gave a tiny yelp before she glared at him. "Really, my little issue and you decided to do that?" she practically growled.

He shrugged, looking rather smug.

Cass glanced up at their guests. The first was either defiantly an alien of he was very unfortunate at birth. He looked like someone had a love child with Mr. Potato head while he was wearing his angry eyes. The second was a young woman, though her appearance was young Cass could swear her nose said she was older, she smiled brightly and welcomingly unlike her potato companion. The third and tallest… was dressed head to toe in black, including a black veil that hid her face from Cass, though Cass could swear the woman was watching her. Her head was angled towards her anyway.

Cass sniffed the air none discreetly. She had lost her urge to be discreet with the Doctor around anyway. She tried to scent the stranger. She did it twice over just to be sure of her findings.

She leaned close to the Doctor, trying to ignore her body's response to their touching thighs and arms she asked quietly "Do I smell a lizard?"


	5. Chapter 5

Chapter Five

The Doctor sat there and laughed at Cass's question, even Mr Potato's offspring and the sweet looking woman where stifling their own humour despite looks of shocked surprise. Cass was inclined to believe that the only ones not laughing where her and the veiled lady.

"Ah, Madame, let me introduce my new companion – Cassidy Williams. She has a good nose."

"I can see that for myself Doctor." The veiled lady sounded amused.

Cass was glaring at the Doctor before she turned back to the three strangers. "Since giggling McGee over there seems a little rude I'll start over. Hello, I'm Cassidy but please call me Cass."

"I'm Madame Vastra" the veiled lady removed the veil with a flourish, revealing her glinting green scaled face, a forked tongue lashing out. She waited a second or too after her dramatic flourish before she continued speaking. "And this is my associate Strax, and my wife Jenny."

"It's very nice to meet you." Cass grinned at them all.

"Forgive my asking, but how did you know the Madame was a lizard?" Jenny asked, looking at Cass with wide eyes.

Cass tapped her nose. "Like the Doctor said, I've got a good nose for it."

"Well I see your taste in companion has not changed Doctor, you did always pick the pretty, young, talented one's." Vastra spoke to the Doctor as though the other three where not there.

The human part of Cass wanted to tell her about her rudeness, however her wolf told her to wait patiently – that Vastra was testing the waters of both Cass herself as well as her bond with the Doctor.

She couldn't, however, hold back the snort of laughter – pleased that the Doctor did the exact same thing beside her. "Young Vastra? Your eyes deceive you, in fact one of Cass's talents is to tell age."

Vastra looked at Cass with interest in her bright green eyes. "If it is a talent of yours, then by all means age me, Cassidy."

Cass's wolf growled, telling her she should be watching for danger rather than playing these games. Cass quietened her canine side and instead concentrated on scenting the lizard woman opposite her. It was harder for her to age someone like Vastra or the Doctor, usually she scented someone's magic and could tell their age from that, but they of course had little to no magic in them, so it took drastically longer.

"Ancient. No offence meant, but you smell like the old bones in the museum in London."

"Jenny then."

"I'd say twenty eight, but that was before she stopped aging."

Jenny grinned and nodded.

"That is _almost_ impressive." Was Vastra's only response. Cass got the idea that this lizard lady did not like her.

Cass wondered if the Doctor had caught on to the feeling coming from Vastra because he shuffled towards her, his arm flu over the back of the bench seat going around her shoulders. Cass hunched a little, her skin warming, sensitive to the slightest touch because of the heat. She resisted leaning into the Doctor – commending herself when she did not give in to the temptation.

The Doctor cleared his throat under the glare of Vastra's green eyes knowing the intuitive lizard had picked up on his protective gestures towards Cass. "So Madame, why did you call us here?"

"Murder of course my dear."

"Why does it concern me?"

"Oh mysterious vanishing people who turn up a day later completely untouched, no bodily markings, and yet their spleens and hearts have been removed. Figured such a disappearing act was right up your alley Doctor."

Cass stopped listening. She knew they were talking but she was looking around the pub – which had been full of midday revellers when they arrived, but was now empty bar for three people and the bartender – none of them where speaking. Cass narrowed her eyes, understanding for the old ways her father had told her about rushing over her.

She cleared her throat gently and turned to the Doctor, pulling back a little bit because his face was closer than she had expected it to be. "I- ah. I'm going to- er – get some fresh air, that okay Doctor?"

He looked down at her, concern evident in the way he frowned. It had taken Cass a while to figure out the different frowns on his almost constantly frowning face, but she was good at is by now. "Is this something to do with-?"

"No. Yes. Maybe." Cass gave him a look before she headed out of the pub – seeing the Doctor and his associates lean towards each other at the table though she was unable to hear their words, she had no doubts they were asking about her though. However at that moment she had bigger things to think about – such as the three men following her with glowing gold, green and blue eyes.

Cass turned to the side of the pub, a small alleyway with a brick wall on the other side, filled with garbage cans and wooden crates. She turned once she reached the dead end – the wolf in her smiled maliciously.

"Who are you?" a blonde man asked, his voice gruff as his brunette associate spat on the floor and made Cass wrinkle her nose. "You didn't petition the pack to come into _our_ territory."

"On a technicality I'm already a pack member – just don't ask me to explain because it's too complicated for your little minds – Bryce, John, Matthew." Cass named the three male werewolves she remembered from her childhood – they were in fact some of the first to contract the illness that killed them all in the end.

The three men looked shocked, sharing wary looks with each other – however just as Cass expected them too, they shuck the impossibility of her knowing their names as if it was as normal as morning porridge. "Not just a delicious trespassing female in heat, one who needs to learn her place too." Matthew growled.

At least eighty years of combat training these men were not familiar with gave Cass and upper hand when the three attacked her despite the dress she wore – and for that she was glad, in the old days she knew exactly what territorial bullying wolf shifters like these three did when they found an unclaimed female in heat. If she was honest the fight released some of her tension built up from the heat – she was glad since it lowered the possibility of her doing something stupid later.

Matthew the pig head who spat went down first, knocked out cold in a pile of trash. Which was when Cass heard someone call her name – she turned to see the Doctor, Vastra, Strax and Jenny at the mouth of the alley two looking shocked and surprised, Strax looked like he wanted to join the fray immediately, but the Doctor – his face was a thundering fury Cass had never seen before.

Bryce and John where between her and them, the shock of seeing her friends had caused them the upper hand. They knocked her off her feet in seconds – and while she was lying on her back, Bryce grinned and sent John after the 'witnesses'.

Which was when Cass felt the rage rise up in her. How dare they threaten her pack? The Doctor – and by association anyone he called a friend or family – was her family too, her pack. The rage overtook Cass- her dress ripped as the wolf surged forward. Cass, in wolf form, knocked Bryce from his feet before racing up the alley, diving on John and taking him to the ground right before he pounced to the Doctor - the shot Strax had aimed at John missing them both by a hair.

Cass felt John's ribs crack under the weight before she felt like she could get off him. He wouldn't be coming after them in a fighting condition anytime soon with five cracked ribs.

Cass approached the Doctor, head and tail down low in a submissive pose, he was only half turned to face her – he was saying something to the other three.

Something heavy landed on Cass's back suddenly and she yelped, startled when sharp teeth dug into the flesh and muscle of her left shoulder. Bryce had shifted to his golden/blonde wolf form after she knocked him down obviously. Unfortunately for Cass, Bryce had always been abnormally large even for a wolf shifter. She nearly buckled under his weight, his thick claws where buried deep into her sides and ripped at her flesh every time she moved to dislodge him. Cass saw Strax aiming his gun, but she ducked with Bryce on her back so the shot missed.

Instead she ran and rolled suddenly, dislodging him from her back bit having fair bits of her shoulder and sides ripped out by his teeth and claws. When Cass stood, Bryce was still down and struggling to stand again, she laid a large paw upon his throat to restrict his breathing and waited until he fell unconscious before she removed it again.

When she returned to the Doctors side this time, he was crouched down waiting for her.

"The enemy still breathes sir, would you like to dispose of them completely?" Strax asked, taking aim at the first unconscious male with his little gun.

Cass snarled.

"No. Not yet anyway. Cass, shift back – I have spare clothes for you." The Doctor pulled a thin, baggy looking dress Cass had insisted they bring out with them this time in case she did go wolf. Twice before she'd been stuck in wolf form on their adventures for a lack of clothing – and once she's saved his life nude.

She shifted back and pulled on the dress quickly – accepting the Doctors help when he pulled her up, she leaned on his afterwards – her blood was seeping through the thin dress, though she wasn't too worried. Wounds like that would heal soon, and it took her mind and body off the burning tingling thrill she felt at the Doctor touching her through the paper thin dress.

"Well Doctor, I see you outdid yourself choosing a companion this time." Vastra said calmly with a tiny smile.

"Madame I don't think now is a time to test Cass as a traveller, she's hurt." Jenny was on Cass's other side now, holding a tiny handkerchief to her shoulder where most of the blood was coming from. The handkerchief was little help, and Cass hissed as the pressing fabric touched her sensitive skin.

"Strax fetch the carriage."

"My scanner claims the dog-boy will have bled out before I reach the carriage."

"She won't." The Doctor sounded furious. "I will not let her die on me, you hear that Cass?" he tightened his grip on her until it was almost painful.

Cass coughed through a smile. "Idiot" she managed to mumble. "I'm not going to die, just let me rest and eat. I'll be fine."

And with that, she passed out in the Doctors arms.

The Doctor was sitting on the end of a double bed in a rather shabbily decorated room in the house Vastra, Jenny and Strax where renting for their investigations up here in the North East.

He was watching Cass sleeping through wide eyes, he couldn't stop his sudden thoughts.

She did not age. She healed vicious wounds within hours. He couldn't help but let his mind wander, Cass was the closest thing to a timelord he'd seen in many years – if he ignored the fact she spent much of her time on four paws.

"Doctor, the Madame is waiting for you." Jenny said from behind him suddenly. "Don't worry, I'll keep an eye on Cass for you."

The Doctor gave Cass a final glance, but left the room without saying anything.

Vastra waited for him in an equally shabby looking tea room. He sat opposite her, waiting as she quite calmly poured tea into little tiny china cups and handed him one. He dumped a lot of sugar in his cup before he took a sip.

"I know what you're thinking Doctor."

"I didn't know Lizards where physic."

"It doesn't take a physic to see when the lonely man has found his equal."

The Doctor said nothing, just sipped his tea and looked over the cup at Vastra.

"She does seem remarkably resilient much like yourself." Was Vastra's only comment.

"Just as stubborn too." He added, using the cup to hide his fond smile.

"But Doctor, you should not get your hopes up. Cassidy probably has a life of her own, she may want to get back to it eventually."

"Cass was a solider when we met – U.N.I.T where using her abilities to their advantage, but they were abusing her rights as they did."

"You don't consider the idea that Cass might have been alright with that, because it helped her protect the rest of the humans you cannot always be there for?"

The Doctor said nothing. He hadn't considered that Cass had been doing good from her side.

Vastra sighed suddenly. "Doctor I am not saying that the girl will want to go back to her other life, but you should keep that danger in mind before you get attached. Even then, she is no invincible. I am sorry I have to be the one to remind you of the fragility of yourself and your companion."

"Trust me Vastra" the Doctor said, glancing down at his hand and noticing Cass's blood still in-between his fingers. "You don't need to remind me."


	6. Chapter 6

Chapter Six

Cass woke up, immediately notching her body was burning with warmth even before she registered the pain left over from her body healing after the fight earlier. She really shouldn't have allowed herself to get cornered like that – especially not with people from her past – but it had the desired effect of taking her mind from her heat at that moment, as well as probably keeping any other wolves away from her and the Doctor while they were there.

It was while she was lay on her side, doing her best to ignore the warm burning under her skin, when she realised there was someone sitting on the end of the bed behind her. Someone who's two hearts made a thumping drumbeat.

She lifted her head long enough to look over her shoulder at the Doctor. He had an elbow resting on end frame, holding his face and messing one side of his silver hair, but otherwise he was most certainly and defiantly asleep.

Cass turned and crawled towards him in the bed. She was aware of her actions that it was the heat taking over and yet she was not struggling against her reaction to a male simply because she'd never seen the Doctor sleeping before. She did however stop before she touched him and settled for inspecting his face instead.

Would she mind so much if she made a move on the Doctor? She thought. Probably not. Maybe he wasn't the youngest and attractive man she had ever met, but he was a good man – even if he had quite a prominent dark streak. Despite his insulting teasing, despite the darkness she could see behind his ice blue eyes, the Doctor was a remarkable man. Underneath his cold exterior he had shown himself to be caring and a little soft hearted… it was quite endearing.

Cass suddenly became aware that blue eyes were watching her. She leaned away from his slowly, blushing. He looked rather amused.

"You must have been thinking hard about something. You were staring at me for a full three minutes." He told her softly. "How are you feeling?"

"Warm." She replied truthfully. "Very, very hot. Is there a heater in here or something?" she tugged at the collar of her nightdress. "No of course not, past not future."

"You healed very quickly. Strax was a little disappointed he did not get to play nursemaid… he likes that role far too much."

Cass grinned thinking of the potato man. Then she frowned remembering how he'd told the Doctor she was likely to bleed out. "He called me a dog." She said grumpily.

"If you bite him later I promise to remove all his weapons."

"And that is why your my best friend." She laughed, then smiled. "Seriously Doctor, I should probably tell you that you're literally all I have now."

"What?" the Doctor asked warily, eyes wide. He didn't want to get his hopes up after Vastra's little chat with him earlier, but it was hard not to.

"I'm a wolf, we're supposed to run in a pack. I never felt a pack tie to U.N.I.T probably because they didn't trust me. But with you, I feel that. You're my pack now, and pack is family." Cass confessed with a sigh. If felt good to admit it out loud.

"I-I'm flattered?" he frowned.

Cass smiled at his uncertain confusion. "It just means that if anyone else tries to kick your ass, I'm going to kick theirs first. And that applies to anyone else you consider a friend – so I'd happily protect Jenny and her gang out there."

The Doctor smiled at that "I think they'd like to hear that."

"I think they already did – they're outside the door."

Cass and the Doctor both hear the sound of heavy footsteps shuffling away. Probably Strax had been lurking to make sure the Doctor was not in trouble when Cass awoke.

Cass inhaled slowly. The Doctors scent surrounded her like a blanket. She leaned forward a bit, catching herself just in time. "Mm, you should probably go before I do something stupid."

He frowned, having momentarily forgotten Cass's condition. "Something stupid?" he asked, turning towards her more.

He seemed to realise what she meant when their noses brushed together slightly.

He placed his hands on her shoulders and pushed her away gently. Cass was a little disappointed, though ultimately thankful he did. "Not that it wouldn't be nice Cass, but your only doing this because of your body." He said as he pushed her further away.

"It'd be great I'll have you know." Cass replied with a wink, but she otherwise leaned back into the bed the rest of the way herself. She bolted back upright almost as soon as she'd leaned back with a sudden "Oh!" She clapped her hands together suddenly. "Vastra said that the bodies turned up without their spleen and hearts right?"

"Yes, why?"

"I remember this."

"Remember- what?" The Doctor frowned suddenly. "Cass please do not tell me we are about to interfere with your own timeline."

"It's not interfering if I remember it happening is it?" Cass crossed her arms with confidence. "It's why I stopped Strax killing those men back in that alley, because they were some of the first wolf shifters to get sick in my pack."

"Cass that's not the point, we could accidentally mess something up."

"We will have to be extra careful then wont we?" Cass grinned and winked. "Anyway I remember out pack having some trouble with a Dhampir. Ever heard of one?"

"No. But I feel like it's going to be something from your supernatural world."

"Anyway, Dhampir's tend to travel as packs too. They usually have a deep self-hatred because they aren't accepted by Vampires and if humans knew what they were they'd slaughter them. Spite for being the outcasts of the supernatural kind of led them to attack everyone and everything that is not a Dhampir. They don't have to feed on blood as often as a Vampire does – but when they do they drink a lot more, so they usually take the organs holding the most blood: such as the heart and spleen."

"You're a walking guide book on this stuff aren't you?"

"Says the 2000 year old encyclopaedia that thought it was fun to describe the process in which dust-bunnies where made."

"We should go tell Vastra about your suspicions."

Cass started to get out of the bed as he stood. "Do you think she'll believe me? She doesn't seem to trust me at all."

"She doesn't trust easy. And that fact your canine and she's reptilian may have some factors."

"Well that's a bit species-ist."

OoO

Later saw the group in the woods, hunting for the Dampier's lair. Cass had wanted to go with the Doctor – a memory of the TARDIS telling her to 'protect him' echoing in her mind – but Vastra had insisted that Strax and the Doctor should tale the left side while she, Jenny and Cass took the right. Cass had a suspicion why Vastra was keen to get her away from the Doctor, and she wasn't wrong.

"So Cassidy. What are your intentions behind traveling with the Doctor?"

"Madame…" Jenny hissed with a frown.

"It's okay Jenny, I expected this." Cass said not sounding at all interested in the situation as she sniffed at a sudden breeze and pointed to their left a bit. "I smell blood in that direction. Anyway, my intention was just to travel. But people keep telling me to protect him, so I guess that's what I'm here to do now."

"And who are these people that tell you to protect the Doctor? He usually does not care for people who do not think him capable of handling himself."

"Well, Im not sure he knows I was asked to protect him. But he does know I considering him pack – which to me is closer than family – so I'll protect him to the death if he needs it. As for who, at first it was just Captain Jack Harkness, he pretty much introduced the Doctor and I after I helped them stop some giant spider attack in London. After him was…" Cass paused.

"Yes?" Vastra prompted. She was looking quite fresh and at home in the forest – not a bead of sweat on her reptilian face, though that was probably normal for her species, while Cass and Jenny where continuously brushing their hair from their damp faces.

Cass bit her lip before she looked over her shoulder at Vastra and Jenny. "Is it normal for the TARDIS to be able to speak to me? Because when I mentioned it, the Doctor seemed very startled."

Vastra and Jenny exchanged equally surprised and a tad alarmed looks. "The TARDIS asked you to protect the Doctor?" Jenny asked.

"Yeah. When he got captured by some jerk with a moustache that planned to have him executed and added to a collection of 'last' things."

"I do not think the TARDIS has really bothered to communicate so directly before." Vastra said, now looking at Cass with curiosity rather than suspicion.

"The Doctor reckoned it was because my mind is half animal it might be more open to telepathic communication."

"If anything having half a canine mind and half a humans would make you a lot harder for telepathic communication to work on you."

"Maybe the TARDIS just liked that I was a challenge then." Cass smiled "You know compared to the 'pudding brains' of humans as the Doctor calls them."

"I resent that." Jenny looked back the wolf and lizard lady.

"I didn't call you a pudding brain, the Doctor did, I –"Cass froze suddenly.

"Cass?" Jenny turned to look at her, frowning.

"Well, this is a great disappointment for us both." Vastra said looking equally as wary as Cass.

"What?"

"We were so busy talking, we didn't notice we were being surrounded until it was too late…" Cass growled a bit, looking into the shadows cast by a cluster of tree's until a pale looking gentlemen with purple slit eyes walked out.

"Your just in time ladies, the games are about to start and we already captured your male cohorts." He said.

Cass snarled, a canine sound in a human throat. "We will not participate in your blood sport, and nor will the Doctor… Strax would quite happily kill you all without needing convincing."

The Dhampir laughed as the others surrounding them came out, grabbing the three of them. Vastra hissed, flicking her serpents tongue at her attackers.

"Oh don't worry, there is more than one way to bait a wolf."

OoO

A long trek, a couple of threats from both sides, and a trip through what only be described as a villainous lair, saw the three women being shoved into a cage where the Doctor and Strax where already sitting on the dirt floor looking strangely cheerful.

"You better not be laughing at us." Cass said, squinting in the half light as she saw a twitch in the Doctors lips when he saw her fall over a rock.

"Of course I'm not laughing. I lost a bet with Strax – I said you wouldn't be caught too." He said, giving her a disappointed look.

"So sorry to disappoint" Vastra glared at the pair.

"Well Cass, you know about these Dampier's. What do you expect will happen next?" Jenny asked, shuffling along the dirt floor to rather calmly take a seat beside Strax. Actually they all looked pretty calm.

Cass tried to lean against the cage bars, but hissed when her skin burned on contact. "Cass?" someone asked.

"Silver. Some myths about werewolves are true." Cass's voice was on edge with a permanent canine growl as she began to pace. "The Dampier that brought us here said they were getting ready for the 'games'. Unfortunately they very much like to pit other supernatural's against each other, usually shifters and vampires. If they think you guys are human you should be safe from the games, they're probably keeping you for food. Vastra and Jenny are probably safe – Vastra's a reptile, her blood is poisonous to them, and if Jenny's been sharing Vastra's blood like I assume she has then she'll be safe too."

"And what about you Cass?" the Doctor asked.

Cass looked away and shrugged. "I'm wolf. They'll probably try to bait me into fighting."

"Will you do it?" Jenny asked after a pause.

"I might not have a choice." Cass sighed, sitting further away from the group and feeling very much like an outsider. "We have until nightfall anyway."

"What happens at nightfall?"

"This place gets filled with supernatural's keen on making a bet on the winner of a fight. Sometimes they even auction off the winning fighters." She sounded bitter and still wasn't looking at them.

"How do you know so much about this dog?" Strax asked, voice gruff and commanding still. Cass was too worried and anxious to be annoyed by his dog remark.

Cass looked at them, eyes meeting the Doctors as a moment of understanding passed between them. His eyes darkened and entire shade, eyebrows twitched into a frown and his mouth became a grim line. He was furious before she'd even started talking. "I've lived a long time Strax, and for most of that I was a stupid teenager, untrained and unable to defend herself. They caught me for the games pretty early on – and when I won they sold me to the highest bidder." Cass pulled down the side of her trousers, showing a deep red burn mark in the shape of a star. "They branded us with silver pokers like cattle." She snarled, sounding more canine than human.

She sighed finally, hiding her mark again, and looking away from them. "You guys should be safe if they think you're human."

Cass turned away from them completely then, deep in thought, she figured she made it obvious she didn't want to talk anymore. She didn't even notice when someone came closer until a hand covered hers and she looked up into the Doctors still angry face. But she was willing to accept his comforting gesture. She moved her hand in his until their fingers entwined, neither looking at the other.

The gesture was not missed by Vastra and her gang.


	7. Chapter 7

Chapter Seven

The Doctor had spent his entire afternoon in complete silence thinking of a way to escape. The men who had captured him and Strax had removed anything weapon like before caging them including the screwdriver.

Strax had tried pushing at the bars to no avail – and more distressing was Vastra noticing the dirt floor of their cage was in fact coated in dried blood and was not naturally this rusty colour.

There were no windows in the room, so it was unclear what time it was, but soon enough the room around them began to fill surrounding a much larger cage at the centre of the room. Some laughed and jeered at the cage, others where scrutinising, inspecting them. The Doctor felt his own lip pull back in a distasteful sneer.

Eventually the sound of snarls where beginning to echo in the room, and Cass stood – the Doctor stood with her unwilling to drop her hand from his. He followed her gaze as she looked towards the door where the viewers in the room where also looking. A large, even larger than Cass, wolf was brought through the doors and quickly locked into the large centre cage. It thrashed and snarled, bright green eyes so similar to Cass's darted around the room as it let out a bloodthirsty snarl. Beside him, Cass gasped – hand flying to her mouth- and her hand squeezed the Doctors tight enough to hurt him.

When the Doctor looked at her he was startled to find tears rolling down her cheeks.

"Cass, are you alright?" Jenny asked having noticed too and found her voice a lot sooner than the Doctor found his.

"Tha-that's my dad." She hissed at the group.

"What?" the Doctor hissed back, having heard her clearly but not quite believing. What other part of her time line where they going to run into while they were here? The sooner they sorted this out and left the better.

"The fur markings… that's my dad, I have the same eye markings as he does. The two white dots above our eyes." Cass said sounding almost dazed. She snapped out of it as soon as she saw the purple eyed Dhampir that caught them approaching the cage, glaring at him she stepped forward and dropped the Doctors hand, taking a discreet step away from him.

"Oh too late sweetheart." The Dhampir cooed as he stood outside the cage, he levelled a gun at the Doctor through the bars. "You come out and fight, or your mate gets it."

Cass paused "He's not my mate…" she said, focusing on the least important part yet to her stressed out mind it was the most important.

The Dhampir shrugged. "Whatever love, you females are all the same. I'm betting you care enough about him that you will get out here and fight just so I don't shoot the bastard in the head."

Cass grimaced and hung her head, giving her answer by pulling her clothes off finding no time for modesty as she shifted into wolf form. While she was changing the Dhampir had unlocked their cage, threatening the others into the corner with the gun.

The Doctor tried to step forward, tried to stop her having to do this for him, but she growled at him with eyes that told him to stay put. He glared right back at her – a heated gaze that told her just how furious with her and the situation he was – before he watched almost horrified as she allowed the Dhampir to slip a muzzle leash over her head and lead her towards the larger cage and her wild father.

A part of the Doctor hoped he would not have to watch her fight. He wasn't the only one of their group who stepped towards the bars again when the door locked and the gun was gone, Strax and Vastra peered out too even they were looking worried. Jenny mumbled something about not wanting to watch as she turned away.

The muzzle was brought off Cass as she was locked into the cage with the larger dun coloured wolf. He snarled and paced eyes locked onto hers while Cass stayed still as a statue, head ducked low and tracking his movement with her eyes. Around them people began to yell bets.

Cass's father lunged at her suddenly, his eyes on her throat, however Cass darted to the right her slim smaller body just managing to keep out of reach. For once Cass was glad she was small and fast rather than bulky and strong like most wolves.

However she couldn't keep dodging forever. Eventually he managed to pin her, and Cass had no choice but to struggle beneath him, her back paws clawing at his belly, she used her front to surprise him dragging him down to her rather than away and biting at his throat – deliberately avoiding the jugular.

He backed off as he yelped in pain, giving Cass time to get up.

Around them people where banging the cage and throwing bottles and other objects demanding more blood. They wouldn't stop until one of them was dead. Was this how she was finally going to die?

Her father lunged suddenly with a snarl and she met him halfway, both balancing on their back legs as the snapped and clawed at each other with growls. Cass threw her weight trying to knock him off balance, it worked successfully and she ended up pinning him beneath her, however once like that she had no idea how to continue without killing him. Could she choke him without killing him and make it look like a death strike?

Cass darted her head forward and enclosed her teeth around her father's throat as he struggled, shutting her eyes tight as she clenched down softly enough to restrict his airway but not enough to tear into his flesh too much – difficult with the amount of fur a wolf has on their neck to protect from such a strike.

When she backed away her ears where down and she met the eyes of her friends in their cage across the room. There where look of confusion and anger to meet her before her view was blocked by the Dhampir who'd caught her coming to remove the 'dead' wolf.

As soon as he entered Cass lunged, fangs embedding themselves deep in the Dampier's wrist and filling her mouth with acidic blood that made her want to gag and release – but she just clamped down harder as his bones crushed and he screamed letting go of the gun.

Gamblers began to back off as they realised what was happening – Cass took the advantage and picked up the dropped keys, leaping over the fallen Dhampir to toss the keys towards the cage.

Something landed on her back, tiny fangs trying to reach her skin as the Dhampir she'd injured did his best to bite her. Cass would had rolled her eyes it the situation around them hadn't been chaos. Vastra, Jenny and Strax had obviously found their weapons and had joined the fray.

Cass loosed the Dampier on top of her with ease, she stood over him, the choice to kill him completely in her hands. He was the last one in the room, the others had either been slaughtered by Vastra and hers or escaped. She stood over the Dampier snarling, fully aware that the Doctor and Vastra were waiting on her, waiting on her choice.

Yes the Dampier was evil, enslaving others to fight in brutally fatal games, and murdering humans for food. But really was it her right to take away his life when she had killed before herself? Sometimes she hated to admit she had even relished in the feeling of killing – especially when she knew others would benefit the death.

Cass stopped snarling, she lowered her tail and ears and stepped off the Dampier. She backed up right until she bumped into something. She looked up and found the Doctor looking down at her, his expression unreadable, he stepped away from her and into the cage leaning down the check the pulse of her father. When he looked up again he was frowning at her. "You didn't kill him?" he said it like a question, despite knowing she couldn't answer.

Cass put her ears down and looked away from the Doctor, a little hurt he would think she had killed him – even if she was destined to do so in the future. Cass turned tail and went to sit in the corner of the room, not looking when she heard Vastra and Strax begin to question the Dampier she left alive. In fact Cass was feeling too… misplaced to do much more than just stare and think hard, until the Doctor brought her out of her thoughts by dropping her clothes down in front of her. She still couldn't read his expression, but assumed this was a strong indicator that he wanted her to shift forms again.

When she sat in front of him, still not looking at anyone, she felt the Doctors hand brush her cheek and with utter surprise looked at him. His fingers lingered on her face for a moment before he stood up and turned to the others.

"Vastra, I think we are done here."

Jenny came over and offered Cass a hand to help her stand up, which she took after shuffling into her trousers again. "I thought what you did was rather clever, and brave." Jenny said in the otherwise hushed room.

"No it wasn't." Cass said simply. "It was a necessary action." She began to head out of the little room, catching the Doctor watching her with the same expressionless face before she looked away from him again. She did not fail to catch Vastra's concerned expression – though she doubted it was concern for herself.

OoO

The Doctor was not one for goodbyes, he never had been, not that he ever just left without a word. He gave his farewell nods to Vastra, Jenny and Strax before he disappeared into his blue box.

Cass stayed outside to say her goodbyes. "It was very nice to meet you all." She said, shaking Vastra's offered hand and surprised at Jenny's hug – Strax's salute was not really unexpected.

"You are a curious one Cass, I am sure we shall be seeing you again." Was Vastra's parting words, they seemed a lot more encouraging than the suspicious way she had treated her with when they first met.

Cass hurried into the TARDIS when she heard a gong that announced the Doctor was getting impatient with having to wait for her, she waved goodbye as she passed through the blue wood doors.

On the inside of the TARDIS the Doctor was prowling around with an angry expression that she suspected he'd been hiding with his blank look. Cass thought better about approaching him and instead chose to lean on the TARDIS railing furthest away from him. After about an hour he finally spoke.

"Why are you hiding yourself away little wolf?" he murmured softly, ice blue eyes staring into hers from across the TARDIS control panel. He was right of course, he usually was. When he moved towards her, she moved away always keeping the same distance between them.

Cass cocked her head to one side like a curious dog, keeping her eyes on the Doctors, as she replied "You are angry."

He took two steps around the control panel towards her and flicked a switch, still never breaking eye contact. "And that scares you?"

"A little bit. The rage of a good man can be very frightening." Cass confessed, noting him take another step.

"Am I a good man?" he frowned, hesitating before stepping towards her again.

"One of the best."

He had taken another step towards her now, close enough that the tips of their shoes touched and Cass could hear the echoing thump of both his hearts, craning her neck backwards just to be able to look up at him since she was so much smaller. "Why are you angry, Doctor?" she asked quietly.

The Doctors hands balled up into fists tight enough to make his knuckles turn white. "Because" his voice shook angrily. "You keep having to do things you shouldn't have to do. You shouldn't have to get hurt to protect me, or be forced to fight. For god sakes Cass after the life you've led you deserve to not have to fight anymore."

"Doctor, you're my pack. I'll always protect you. Fighting is just a part of what I am." Was Cass's quiet reply.

"But I don't want you to get hurt. People always get hurt or worse around me."

"I can heal better than most Doctor, I'll be fine."

"You're not listening Cass" he insisted "Whether or not you can heal yourself is not a fact when I feel like I've been punched in the gut every time I see you get hurt." He brought his forehead down to touch hers, an intimate contact that surprised Cass.

"Doctor…?"

"Why?" he asked, eyes closed as he leaned on her. "Why do you put yourself in harm's way because of me?"

"Because…" Cass began, her voice soft. "Because you're worth it. Because you deserve to be protected for a change, because if I don't do it who will, and where would the world be without you, because I can protect you…and…"

Cass had brought her hand up to the Doctors cheek while she was speaking, surprised that his tough looking face was surprisingly soft and smooth. She had felt a man with so many unseen battle scars should feel rougher than he did…

"And?" the Doctor urged, not even noticing the contact of her hand.

Cass could think of nothing else to say that he might understand, and acting on utter impulse she reached up and slid her mouth over his in a chaste kiss, once again surprised at the smooth feel of him rather than the roughness she expected. She had no idea if he would understand her gesture at all, but before he could say anything in reaction to her move, she had darted out of the control room, leaving him standing there.

She could swear the TARDIS was laughing at her as she bolted to her room and threw the locks on the door – keeping him out or her inside she hadn't the foggiest.


End file.
